SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c63eca95bab29bbb110f5a82c21f68091dc792ffa2b10e14d497a728ec980147' 
  AND token = 'P41tOsd2+aLVjADTTdDzQzU3mfblhOGlHXREALpCsQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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