SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f692d84d4f336cb7c5083bc0336624f95d176e223c448835aa3718de1a147fc6' 
  AND token = 'yTyjYzo+GGY0tAS+65H4S1sHWsfDOODZgmJDDR435rM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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