SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c932915635a696ecb048c20708c1b0902e9e02b6f2c8eadaa375f6078ccc040' 
  AND token = 'I1MDL6eSQW3BCAwQlwn2AUSPqoGxDiSax1V+92bN7Mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}