SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c4e98a1d27fbd0ed8604c6cb7b4033173a4eabbdaa7f45f3f732c1905e19724' 
  AND token = 'LhTL+oJLetY1SZY8m7yRzEDLUbUmTkSpjUUdrB1L6UA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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