SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0f53807d2eb89ccee4f0bda343597f7f733255f528b86a08d5be9f3a4f94449' 
  AND token = '08TRD+hfcs2wQuOeuvaMiPESeyBdeP2ixG45noe6p1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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