SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe7c51ef1f9ced127278022578fc5f2de9030071ddfebc1ba500798840fc16a5' 
  AND token = 'ReEXVwTglMU/VU68G4gAYLE6E/J3bLL23KN2Qi7L5/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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