SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1d7992a277365746954fff34358def134d6bf5fa42cc0e4c5e1cd784bb18ba0' 
  AND token = 'ju+nBhzrn895/qdkDbCLk0feHIukq5s+Jp70OYmjjjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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