SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '763a0dd7ef35484d6917ca2297f87a062f7a9cc2105bd549a0e6c4fed851b1bb' 
  AND token = 'dWkhpLZkvlagviCUK/36jSyaFvgHXNduXkN1zzHIVOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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