SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee13dbae413ecd949aab6fcb9e6fe2d0dff0d9694474ab173adcf2d0e6a4559d' 
  AND token = 'dYYgFV7/f1kGQ1Ez6X9PiljArDBzUOzpOsdVb6Gcwlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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