SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fd21b99274504f96deb43402722fd626fb6fb93a0cf194d355379e3a125523b' 
  AND token = 'vRePYNNoSFDIV/K6SG0VHDvihZ9EujC+Z3N+EnxGu6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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