SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57165db9c5bb535b034cbe9906b8269cd9292d6ddbe4320c7197e6b8582f962' 
  AND token = 's5HurT/ubLMrpjhoB8dAyJZHd3ewjPzqMU1L6iuuhmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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