SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aadf32829ac44678ba56b51af218da689fa22427d20408bfe3856db0926bfe61' 
  AND token = '8mB+BXRPY1uvH7FDuj6pgHyYwBRvPBghYrgm95+EX6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}