SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c660032b55a1a86d4f8900dfa29662d595ef5c3f1792faa63d2783c7bb9b5c6b' 
  AND token = 'ljQnGrxzktGLE8MAMHrrMIg6D/ymaa//4YpV1wDeGU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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