SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e7f0554187eaa340988471d1aeb9abaf5814b0b47a51d0eb77d3792cfec4ff19' 
  AND token = 'H3s8jmZpH11gp4aG2Xm/m5txvRCcPayJ/PPUBa23Xxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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