SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7953782bfc9e93388a65423e7e1f8d0642c1d6a6aebaa4309bfa9a23a2cdf601' 
  AND token = 'eWla9PvGT7gbXjbuEuGvcBzgsZ9QVTVZYD2uWFsuuzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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